Don't Stand So Close to Me. Create 5 groups (from 2 to 5 various directions). Every group should include the class having a speed buff (e.g. blink, sprint, disengage, teleport) and the other class without it. When they reach the center the fast classes'll need to cast their speed skills as quick as they can. As a result, they will be a little bit ahead of the slow classes. Once they reach range, they will be able to split as there'll be some space for them. Keep in mind that some of the achievement tracking addons may show false warnings.
Taste the Rainbow. This achievement can be made in multiple kills. If the raid players are experienced and have got some good gear, then they can concentrate on all combos instead of doing the classical killing priority. Nevertheless, the combination of purple and yellow requires some awareness from the players: for instance, don't use shields or heals very often, and don't forget to use cooldowns for your defense. Besides that, think about letting all 3 through in normal mode towards the ending of the battle.
Ping Pong Champion. Everything’s pretty clear here. Most surely, it will bounce about 13 times as the orb spawns beside the ranged group. So, all you need to do is to assign 2 or 3 people (where 1 player is melee and others are ranged) who have cooldowns for the last 3-4 bounces. The other part of the team should go far away, it'll help them avoid the explosions and stay alive.
Holding Hands. The first thing to check is the pets (they should be behind or in the mid) or it won’t work out. After that, you should create a line with player within every 6-10 yards along the platform's edge. Start from the last crystal thing which doesn't work and move forward the activated one. You have to keep away from the activated thing: thus, your players won't be hit by the lightnings. Then make sure that every player stands in his position and the last person goes to the active crystal to close the circle. Do not forget that all players should stay right in their positions in the appropriate distance (within the distance of 10 yards) as the rewarding of this achievement takes a few seconds and the wrong position won't result anything.
Minutes to Midnight. Here, seven players with defensive cooldowns should be assigned. Deck Defender - you should assign players and divide the deck into several areas. Everybody within reach has to run into the barrage (several people will be enough). When the twilight onslaught phase comes, mobile classes (like mages) should stay in the mid of the deck, so that they can backup the barrages which are in the distance. What makes the situation much simpler is the high damage with which you can hit the drakes. As a result, the less the drakes, the fewer the number of barrages!
Maybe He'll Get Dizzy. Just after the pull you have to kill 1-2 tentacles and turn left. There kill 1 tentacle and turn to the right side. After that act as usual, but don't forget to turn left after the 1st plate and turn right after the 2nd plate. Of course, you may kill fewer tentacles in the first sequence whey you roll 2 times, but that's really stressful to your healers because of the beam. The achievement will still be yours if you make him turn more after the sequence.
Chromatic Champion. To get this done you'll need about 1 to 4 resets (or even 6-8 if your team is bigger than 8 players). We suggest you to kill orders, but start from the simplest one. The first three order won't be really difficult for the raids with experience and good gear. However, the last one is much more difficult to win.